New Physics Beyond The Standard Model And LHC Test

We study new physics beyond the standard model in particle physics, which hastwo important aspects: one is to study the electroweak symmetry breaking mechanism,analyze the experimental results and predict new physics signals on CERN LHC; theother is to study the quantum gravity, which is not included in the current standard modelof particle physics, and its important role on the gauge force unification. For the firstaspect, we study the top quark seesaw mechanism, in which the top quark couples witha SU(2) gauge interaction, acquiring weak scale mass via the seesaw mechanism. Wepredict a pair of new gauge bosons (W′Z′), a pair of neutral Higgs bosons (h0H0), anda pair of heavy quarks (T B) as required by anomaly cancellation. The the unitarityof longitudinal weak gauge boson scattering is preserved by both Higgs bosons (h0H0).We systematically study the electroweak precision measurement parameters (S T W Y),and derive constraints of theoretical parameter space from experimental data. We furtherpredict and study the new signal on LHC for the125GeV Higgs boson; we find that theevent rate for125GeV Higgs boson decaying to di-photon is enhanced compared with thestandard model, which is well consistent with the latest experimental results from LHC.We also give the latest experimental search limit for new gauge bosons (W′Z′) and theheavier Higgs boson H0, and systematically analyze the future discovery potential of theH0Higgs boson on LHC.On the other hand we systematically study the quantum corrections of gravity to theother three fundamental interactions. One long-standing problem on this subject is thatthe result of running coupling calculation depends on the gauge parameter and the choiceof gauge fixing, we first adopt the Vilkovisky-De Witt effective action method to calcu-late the gauge-independent quantum gravitational corrections to gauge interactions, andfindthatthequantumgravitycorrectionsmakethethreefundamentalgaugecouplingcon-stants approaching an ultraviolet fixed point at very high energy scale, thus realizing theultraviolet asymptotic freedom for the electromagnetic, weak, and strong gauge interac-tions, pointing out the possibility of unification of the four fundamental forces at Plankscale. We also systematically study the quantum gravity correction to the standard modelHiggs field self-interaction, deriving stronger triviality bound for the Higgs boson mass.